Pressure relieved explosion chamber



Dec. 22,1959 5, CLARK 2,917,927

PRESSURE RELIEVED EXPLOSION CHAMBER Filed April 22, 1954 2 Sheets-Sheetl GEOPGE I. CLARK,

AGENT. I v

Dec. 22, 1959 e. F. CLARK 2,917,927

PRESSURE RELIEVED EXPLOSION CHAMBER INVENTOR.

GEO/26E I: CL/LQK,

atmospheric pressures.

, 2,917,927 Patented Dec. 22, 1959 v 2,917,927 PRESSURE RELIEVEDEXPLOSION CHAMBER George F. Clark, .Los Angeles, Calif., assignor toHieatt Engineering Company, Burbank, Califi, a corporation of CaliforniaApplication April 22, 1954, Serial No. 425,016

s Claims. ((11. 73-432 This'invention is concerned with a pressurerelieved explosion chamber useful for environmental testing of devicessuch as explosion-proof machines, and such that predetermined internalpressure conditions can be established Within the chamber and maintainedunder various external pressure conditions. For instance,super-atmospheric or sub-atmospheric pressure may be maintained withinthe chamber regardless of the pressure which exists at the outside ofthe chamber.

It is desirable in many situations to test or maintain explosion-proofmechanical devices, or the like, at given predetermined pressures duringtheir operation in order to establish the fact that they areexplosion-proof. Such chambers are particularly useful for testingincidental to the perfection or development of aeronautical devices andequipment, and must be operable at various altitudes or For instance,the chamber'may be operated at a place which is at sea level, or it maybe operated at a .place of any lower or higher altitudej 1 A generalobject of the invention is to provide a valve controlled chamber of thegeneral character referred to, which is of heavy or substantialconstruction in order to withstand the internal and external pressuresto which it may be subjected, during operation, while at the same time'the structure is "compact and simple in construction and highlyefficientin operation.

It-is another object of therinventio n to provide a valve for anexplosion chamber of the character described which is operable undervarious external pressure conditions to immediately relieve explosivepressures developed within "the chamber.

A further object of theinven tio n is to, provide eflicient means'fordirecting or charging mixtures or, gases into and exhausting themfromian explosion testing chamber in thfe'character' referred to."

, f It:is also an object ofthe present invention to provide an fleffective ineansjfor evenly distributing and circulating anpreferablyidome-shape'd and; arranged 'with their con- :cav'e sidesinward, the closure being joined to the main ."section of the bodyby-one orj r'norehinges and being held closed by a'suit'able lock means.The several-parts of the'body, as just referred to, ar"epreferably'-formed of steel plates of substantial weight or thickness togive the fstrlicture the desireds'trength against being crushed orbollapsedwhen the chamber within the structure'is exhausted,and-fror'hibursting when;the explosive pressures A test'upport-is'provided iii connection with body "-fQr 'ca'rryingthe deviceto be tested, and such support in-' i volves a base-which is movablycarried on rollers so that tracks which'are provided along the lowerportion of the body. A means is provided for exhausting air from theinterior of the body, which means includes an exhaust pipe or lineconnected to a suitable suction pump. The line is under control of avalve. A means is provided for pressurizing the interior of the body,which means includes a pressure line connected to a pressure supplyline, a shutofi valve in the pressure line and an adjustable pressureregulator.

Air conditioning means is provided by the present invention and includesa blower adapted to deliver air to a ducting system which is adapted todirect the mixture deliveredby the blower into the interior of the body,or alternately to the exterior of the body where it is-exhausted fromthe chamber. The air conditioning means also involves a circulatingblower which receives air within the body and is adapted to deliver theair through a flexibleduct, as may be required under special conditions.An ignition means is provided for exploding the mixture within thechamber and includes a suitable spark or glow plug under control of aswitch at the exterior of the chamber; 7 i

The valve which is provided by the present invention is quick acting,and is adapted to immediately respond to pressure within the body of thechamber, whereupon the valve is immediately released or opened. Thevalve is preferably large and of such capacity as to handle largequantities of gases which are likely to escape from the chamber. Thevalve involves a cylindrical seat element and a simpledisc-shaped valveelement which is movable relative to the seat. An operating means isprovided for the valve-and is operable to hold the valve closed againstthe pressure withinthe body. The operating means involves a cylinder andpiston mechanism which is carried by the body of the chamber, and whichis connected to the movable valve element. A pressure line is connectedwith the cylinder above the piston so that pressure is exerteddownwardly against the valve element forcing the element into engagementwith the seat.

A valve control means is provided for applying pressure to the operatingmeans above referred to and involves a pressure-line under control of anadjustable pressure regulator. The pressure regulator controls thepressure applied to the cylinderand piston mechanism so that the valveelement is held with the desired force against the seat. The controlmeans also includes a pressure release valve which is adjustable andisadapted to relieve pressure from the cylinder and piston mechanism whenthe pressure therein reaches a predetermined limit; A 'safety valve isprovided for releasing extreme pressures'frorn the chamber underextraordinary circumstances.

The various objects and features of my invention will be fullyunderstood from the following detailed description of a typicalpreferred form and application of my invention, 'throughoutwhichdescription reference is made to the accompanfingdrawings, in which:

Fig. 1 is a sectional view taken longitudinally and vertically-throughthe chamber that I haveprovided and showing portions of *my inventiondiagrammatically. Fig.32 is'an enlarged detailed sectional View of thevalve that -I have provided taken as indicated by line 2-2 on it maybe-oper'atedto and 'fronrthe interior of the body on i valve ina'difterent position, andFi'g. 4 is an enlarged view-of the valveelement taken as indicated by line 4-4 on Fig. 1.

The structure provided by the'present invention involves, generally, abo'dy A WhiCl'l'fOI'IllS a chamber Y, a closure B closing one end of thebody, a test support C within the body, an exhaust means D adapted toestablish' sub-atmospheric pressure within the body, a pressure meansEadapted to apply super-atmospheric pressures to the body, an airconditioning means F for charging into, exhausting from, and circulatingair mixtures Within the body, an ignition means G for igniting mixtureswithin the body, a valve means H for dumping gases from the body, anoperating means I in connection 'with the valve means H, a control meansK for the operating means, and a safety valve L for the body.

The .body A, as provided by the present invention, .is in the form of acontainer or chest, and it is provided as the element .or structureserving to withstand internal and external pressures. In its preferedform the body involves, generally, a cylindrical case 10 and a closure11. In the case illustrated the body has an elongate cylindrical mainsection 12 and an inner end 13 closing the inner end of the main section12. The inner end 13 is preferably dome-shaped and is integrallyconnected or joined to section 12 as by welding W, or'the like. The end13 .is joined to section 12 so that the concave side of the end 13. isinward, as clearly shown in Fig. 1 of the drawings. The closure ,11 ispreferably a dome-shaped part orunit joined to the outer end portion ofthe section 12 by one or more hinges 14 and releasable latches orfasteners 15. The closure 11 is arrangedwith its concave side inward asshewn in Fig. 1, and it is preferably made to correspond in size ordiameter with the outer end of the main section 12. A suitabletransparent inspection plate 12 is provided so that the interior of thebody is visible. A sealing means is provided .to establish and maintainan air-tight seal between the closure 11 and the case 12 of the body. Inthe preferred formof the invention the sealing .means involves an an.-.nular packing ring 16 arranged to occur between the fl nges" 1 d 1 Ah 1p 'i ts pw dly r m .the {top of vthe body A and ,is characterized by asimple rect nsu ar p di lement op n a t e top heshielt 17 encloses thevalves, H and L.

The test supportC is located within the body A and involves a base 20movabl y carried on rollers 21 engaged ontraclrs 22. An electromechaniealdevice or mechanism in the form of a motor generator X is shown monn tedon the test support C, which device is typical of the type of mechanismadapted to be tested within the expiry,- sion chamber which I haveprovided. An electrical test panel 23 is provided and located at theside of the body io t a nst e e i a s rc ts n cess r for en a- .tion ofthe device to be tested, such as themotor genen- Q X- l ea Where hefldei t e e te is b l y a d f ons der e ht r a s mp e ma e q m unt e uni -st e b ss and th i e he bas :20 and deyice [t a the tested into positionwithin the body A.

Th ix an fm a s D pr i ed e rem n te ses from the interior ofthe case12,.involves a pressure. 1;- nectionQS-betwen the case 12 anda suctionpump T ca n i en 2 may e a epi e q n ct onead it may carry a controlvalve 27 adapted to be opened or closedas circumstances require..Thehpurnp 26,,rnay een ta e st on r a t at napi mr-an sd ve by asuitablernotor 28, such as an electrie motor, ortth e be driven by themotor toevaenate. the.interinr o f;tl 1e case 12 when the valve 27 isopen, l

The pressuremeans E, provided fo'r introducing-air into the interior ofthe case, involves a pressure line ,;30

extending between thecase Q12 and apressure supply 31.

A q 'g a e 2m ax r su eresulatin a e 33 are arnedin th ine .30 to $12.91 heair flow in; case 1.2, The v l e .2 may be. a imp eshut-qt yam andt P e s re re la in valve L33 may b dju t ble electric rnotor or thelilge, and a reser voir 36 for-storing t ai s mpress qbytherymp3 Ihes ppy 1.31 may be scrawled-lay su table t est lat i a repay which is adaptedto stop the operation of the pump 34 when the desired pressure isreached within the reservoir 36. "By adjusting the valve 33 to thepressure which is desired within the case 12, and by opening the valve32, the deinterior of the case 12.

The air conditioning means F, provided by the present fan element 47rotatably carried on a shaft 48 entering the end 13 of the body A. heShaft 48 is earried in a bea n 49 su p rtcd b th a 13 of the bash/ant ns t e b dy .A th o a suit islan or park in 50 i a t Theaireirculating'fan 42 istcharacterizedbya barrel: type blower elernent 51 located adjacent to andconcentrip th-ti e e eme t 7.- a he d m n fi i alsa d 9. the haj 8 and i ard et the e ment 7 a shown in Fig. 1 of thedrawings. Ilfhedrive 44.n1ay be syita le mm; su h-as an-sl st motor the1 i s shows in the ra i 'skt e lem ts 4 n .5 are ar ed an d e tlqssth ras a i and are rrete bl bar el-ty e n uni whir r ce air axia ly at thcente e era de ver a r tangen all them the peri he y-memoir r i t Thedis i vt aa du ting 43 e eiv s th ir-m xture d i ered lat/the b qw e emet whil the ble 85 el men tfil ds e s a dime-1 me the p eriqr at e y A iseat; s su a ipn Wit in the bo y. A fie ibisu t 53=I 1 b pr ided p me vpair delivered by th eames 5! anti m s i ute i w thi he heat s?ia-themaan desi ed,- The di i ti n du i sl a receiving duet 55 joined toand receiving air delivered by t e b we e e e t 7 a h ias u 6 e en iniron; th d st 5 nd de iver n air int the W4 A, and a discharging duct57- entending from the duct 55 ans iver n air-int h atmqs h s urr u myA, ;.P. a b.1, 41 95 219 447 asalwwa i a he d aw s Asui able alvefifi iPm i ed a thes :Qf hs tha 55 and is adapted to direct air into the ductsfilwil Que nq tiqn anti nt the d st wh n the other rar i s A su tab ve59 9 Fi i l dllF and a sim le sweat! valve t r. eve t n 4 9 P at?through the duct 56 into the ehamber Y. It will be readil -und used. 1 9th valve ma be manip a to mam} theai ii lw eith o ic wlateiair mm thesherbet 0: 9 ex t i th reimm- B d mmin e air into the duct 56throughoperetiqn of the valve 5g, si s rbmigasasti s a; 19595 .tq th warsm ra s rovided-by t e p ssati avsp- 1 d t ie plqs s themixtu e ea nedwithin t. -Afte heenvimnm n a te nso 1a tl i h s the was wa he thed v e.i op d succ ssfully sad i h a manner a to have t W ap s vem m e th qdy,it be es neeessary r 4 was w h the ast y ipprds t tle ermine as a iat-ha t senmm letes ted in rde to g o e than! du n p r qn 2 siredpressure is supplied from the reservoir 36 to the' The delivery fan 41is characterized by a barrel-type A quickly andimmediate'lyreleasingp'ressure which, is developed within the body. A. As shown inthe drawings, there may be oneor more valve units H, and each involves,generally, a seat 65 and a valve element 66 movable relative to theseat. ried on a vertical axis in which case the valve seat is.horizontally disposed and the .valve element is moved verticallyrelative to the seat as thevalve is opened. The seat 65 is'preferably'acylindrical partcarried at the top of the case 12, enters the case, andis characterized by an inner cylindrical wall 67 which :forms an Openingin the case 12 of the body. The cylindrical seat 65 ex-.

tends from the .interior ofv the body A and projects upwardly andterminates at the exterior of the body in a flat horizontally disposedface 68. The valve element 66 is preferably a simple -flat disc-shapedpart and is engageable with the seat 65 to close off the interior of thebody .A from the atmosphere at the exterior of the body. -The valveelement 66'is somewhat larger in diameter than the seat part 65 and isprovided with a seal 70 of rubber, or the like, engageable with the face68. When the valve element 66 is engaged with the face 68 of the seat 65the seal 70 prevents leakage between the parts.

' The valve operating means I is provided for holding the valve element66 in pressure engagement with the valve' seat 65 and involves areciprocating or cylinder and piston mechanism 72 which is coupled toand.carries" the valve element 66. The cylinder and piston mechanism iscarried on a vertical axis concentric with, the seat.65 and valve 66,and has a cylinder 73 which slida'bly carries a piston 74. A piston rod-75 projects.

downwardly from the piston 74 and isengaged with a boss 76 on the upperside of the valve element 66. i It will be readily understood how theareas of the valve element 66 and of the piston part 74' arejrelated sothat a differential pressure is applied to the cylinder and pistonmechanism 72 in order to hold the valve closed against the pressurewithin the body A.

The valve control means is provided for applying a constant pressure tothe valve operating means and for releasing said pressure when anexplosion occurs within the body A. The means K involves a pressure line80 extending from the pressure means E hereinabove described,'a-pressure regulating valve 81 in the line 80, pressure lines 82receiving pressure from the line80 and regulating valve 81 anddelivering it to the cylinder and piston mechanism 72 of each valveoperating means, and a pressure release valve 83 in communication withthe lines 82'. The pressure regulating valve 81 may be any suitablyadjustable regulating valve, and the pressure release valve 83 may beany suitably adjustable pressure release valve.

In order to operate the valve in the desired manner, it is merelynecessary to adjust or set the regulating valve 81 for a pressuresomewhat in excess of the pressure which prevails within the body A,while the pressure release valve 83 is adjusted or set for a pressuresomewhat in excess of the pressure delivered by the regulating valve 81to the lines 82. When an explosion occurs within the body A immediateand extreme pressure is exerted upon the cylinder and piston mechanism72 forcing the piston 74 upwardly and compressing the air above thepiston and in the lines 82, whereupon the release valve 83 operates toallow the excess pressure to escape so that valve elements 65 arereleased to move upwardly. After the explosion has expelled the excessgas from within the body A the release valve 83 will close and allow thepressure delivered by the regulating valve 81 to force the valve H backinto a closed position.

The safety valve L, which I have provided, is for emergencyconditionsand is set for the maximum pressure to which the structure may besubjected, and involves a seat 90 and a valve element 91. The seat andvalve 90 and 91, respectively, may be constructed in The valve Hispreferably care.

valve L is operated into a closed position by means 'of a suitablecompression spring 92 engaged against a stop 93' carried within the seatand operating the valve 91 .through a rod 94.

Having described only a typical preferred form and application of myinvention, I do notwish to be limited or restricted to the-specificdetails herein set forth, but

wish to reserve to .myself Iany variationsv or modifications that mayappear to those skilled in the-art and fall within the scope of thefollowing claims:

- Having described my invention, I claim:

1. 'In combination, a chest-like case having a chamber and a closuretherefor, a valve in communication with the case and having a seat facedaway from the chamber and a movable valve element engageable with theseat, an operating means for the movable valve element including areciprocating mechanism to shift the valve element to engage onthe seatand to be unseated upon an excessive. pressure within the case, andacontrol means for the operating means including a pressure linesupplying fluid pressure to the said mechanism to hold the valve elementengaged on the seat below said excessive; pressure and an adjustablepressure regulating valve in said line maintaining said fluid pressureto hold the valve element engaged on the seat belowv said excessivepressure.

.2. In combination, a chest-like case having a closure, a valve incommunication with the case and having a seat and a movable valveelementengageable with the seat, an operating means for the movablevalve element including a reciprocating mechanism to shift the valveelement to engage on the seat and to be unseated upon an excessivepressure withinthe case, and a control means for the operatingineansincluding a pressure line supplying fluid pressure to the saidmechanismto hold the valve element engaged on the seat below saidexcessive pressure and an adjustable pressure regulating valve in'saiclline maintaining said fluid pressure and a relief line from the saidmechanism and a pressure release valve in said relief line, said casenormally containing a given pressure therein, and said release valvereleasing pressure from the said mechanism at a higher pressure than thepressure maintained by the regulating valve when ex-. cessive pressureoccurs within the case;

3. In combination, a chest-like case having a closure, a valve incommunication with the case and having a seat and a movable valveelement engageable with the seat, an operating means for the movablevalve element including a reciprocating mechanism to shift the valveelement to engage on the seat and to be unseated upon an excessivepressure within the case, and a control means for the operating meansincluding a pressure line supplying fluid pressure to the said mechanismto hold the valve element engaged on theseat below said excessivepressure and a pressure regulating valve in said line, said regulatingvalve normally maintaining a pressure in the said mechanism higher thanthe pressure in the case.

4. In combination, a chest-like case having a closure, a valve incommunication with the case and having a seat and a movable valveelement engageable with the seat, an operating means for the movablevalve element including a reciprocating mechanism to shift the valveelement to engage on the seat'and to be unseated upon an excessivepressure within the case, and a control means for the operating meansincluding a pressure line supplying fluid pressure to the said mechanismto hold the valve element engaged on the seat below said excessivepressure and a pressure regulating valve in said line and a relief linefrom the said mechanism and a pressure release valve in said reliefline, said case normally containing a given pressure therein, saidregulating valve normally maintaining a pressure in the said mechanismhigher than the pressure in the case, and said release.

